Do I measure the product itself or the carton after packing and bubble wrap?
Measure the outer carton once it is packed and sealed, and weigh it ready to go. The carrier never sees your product, only the box it travels in, and it measures and weighs that box as it is. That is why the tool's steps ask for the packed length, width and height.
The product alone gives a comforting, wrong number
Open the product page in your store and copy its dimensions, and you get the size of the bare item. But nothing ships bare: there is bubble wrap around it, filler on top, then a carton with its own wall thickness. Each layer adds centimetres in all three directions, and the volume multiplies because it is the product of those sides.
The gap in numbers
A product measuring 30 × 20 × 10 cm and weighing 1 kg. Wrapped with bubble wrap and filler at about 3 cm on every side, the outer carton becomes 36 × 26 × 16 cm and weighs 1.3 kg. With 5000 as an example divisor:
- The product alone: volume 6,000 cm³, volumetric weight 1.2 kg.
- The packed carton: volume 14,976 cm³, volumetric weight 3 kg, which is the chargeable weight.
- The actual weight went up by just 0.3 kg, while the chargeable weight grew 2.5 times.
Build your shipping cost on 1.2 kg and the real bill arrives at 3 kg. That gap repeats on every order of this product.
Measuring the finished carton properly
- Pack a real order the way you normally do, with the same carton and protection.
- Measure the outside, from the furthest point to the furthest point, including any bulge in the sides.
- Weigh the sealed carton, not the product on its own.
- Enter the figures in the Volumetric shipping-weight calculator with the divisor your carrier gives you, and keep the result for that product.
Can you narrow the gap?
- Choose a carton close to the product's size with just enough room for protection, and no bigger.
- Some products come in a sturdy factory box, and one outer layer may be enough instead of an extra carton.
- Fragile items need real protection, so do not trade safety for a lower weight. Cost safe packing properly and build it into your price with the Selling-price calculator.
If you ship several different products in one order, the rule is the same: the carton leaving your hands is what gets measured. Note its contents and dimensions on a packing list with the Packing-list generator.
Common questions
Do the carton flaps or shipping label count?
Yes, if they stick out. Measure the final shape as the courier will receive it.
I ship a product in its retail box with no extra carton. What do I measure?
The retail box plus any wrap you add over it, because that is the parcel in this case.
Do I measure every order?
No. If each product always goes in the same carton and packing, one measurement is enough.